1. Field of the Invention
The present invention relates to a transducer capable of performing modal testing or non-destructive testing of a rod member, and more particularly, to a non-contact type transducer for performing structural diagnosis of a rod member by performing non-contact excitation of the rod member or detecting a signal propagating in the excited rod member.
The present invention is derived from the research performed as a part of the New Technology Research & Development Support Project carried out by Korea Engineering and Science Foundation and Seoul University Industry Academic Cooperation Foundation.
[Project Number: 2009-0083279, Title: Multi-Scale Paradigm for Creative Design of Multi-Physical Complex Structure System]
2. Description of the Related Art
When a machine device is being designed or checked, in many cases, modal testing may be performed to diagnose structural stability. Resonant damage and wear-off due to vibration caused by operation of a machine device may be prevented by obtaining information regarding natural frequency and mode shape through modal testing and designing the mechanical device in consideration of the information. Accordingly, structural stability of the machine device may be improved.
To perform modal testing for figuring out vibration characteristics of a member constituting a machine device, it is necessary to vibrate the member to be tested and to detect the vibration.
FIG. 1 is a diagram roughly showing a method of performing modal testing in the prior art.
As shown in FIG. 1, in the prior art, a member to be tested 2 is generally vibrated by a person using an impact hammer 80. Furthermore, a commercial accelerometer 70 is attached to the member to be tested 2 to detect signals transmitted through the vibrated member to be tested. However, in cases where a person vibrates a member to be tested, repeatability of the test cannot be guaranteed.
Therefore, demand for development of a method and an apparatus for uniformly vibrating a member to be tested and detecting the vibration during modal testing has risen.
Furthermore, in addition to modal testing, it is difficult to perform non-contact type structural diagnosis of a machine member through non-destructive testing. Especially, in cases when a machine member is already installed, it is difficult to perform contact type structural diagnosis, either because it is necessary to disassemble the machine member or because other machine members may interfere.
Therefore, a demand for development of a transducer capable of easily performing structural diagnosis has risen.